So. I have big flat roof on my commercial building in Milwaukee, which I turned into a vegetable “farm” using raised beds. Last summer was my first season, and the results were good enough that I decided to start a CSA, with the goal of selling 10 shares. One of the advantages of a raised bed garden (the roof helps but mainly it’s the raised beds) is the ease of season extending.
While most CSAs aroound these parts prepare their first market baskets sometime in late May, last week was my first. I expect go keep them coming well into December. The varieties right now are limited to lettuce and greens, but fresh whole heads of buttercrunch ready in early April? Are you kidding me?
Starting lettuce and greens in Febrary in zone 5 the easy part. More difficult will be making a blog about it interesting! The answer (not to making things interesting) is hoop houses. I took 3/4″ pvc pipes and arched them from one side of the box to the other, drilling holes in the top of the box in which I could seat the pipe. This is covered with 6 mil plastic, and, voila, instant heat whenever there is sun. I have also built some ones with clear corrugated polycarbonate sheets. These reflect less light and are useful inside the “greenhouse.”
The single hoop house does not really cut it around here. Afterall, I started transplanting lettuce, arugula, broccoli, spinach, kohlrabi, broccoli raab, and planted radishes and onions on February 11th. As of April 1st I has transplanted about 10 tomatoes and now am up to about 20. Beans, peppers, and cukes are all starting to go in. The trick is a double hoop house–really a makeshift greenhouse made with steel tubing and plastic, covering half of my raised beds with their hoop houses. When I figure out how to do it, I’ll add some pictures to the blog. But starting more seeds and weeding, watering, and transplanting is a more pressing concern for me these days. A hungry mob of angry CSA subscribers is all I need!
The “greenhouse” and the hoophouses get very warm during the day. Even in February, I was recording temperatures over 100 degrees, at which point I started venting the greenhouse. Night is a bigger problem, as the air temperature drops suprising close to the outside temperature, at least with my “system.” But the soil warms and the seedlings are hunkered down close to it, and almost all survived some nights with single-digit temperatures.
This is all experimental to me. I had no idea what would survive and what wouldn’t. I have no training in this. I’m just some nut who planted a garden on his flat roof. Last fall I planted a lot of stuff that I thought would provide some winter snacks. Most of that didn’t work. My early plantings have, however worked pretty well. Next year, mini cows.
Btw, I just tried to upload a picture, but I don’t know where it went.